We have two LSC400B controllers, which we were using with SuperLab4.5 (and earlier with 4.0).
Now I have SuperLab 5.0, with which I was trying to connect and use one LSC400B controller. It was not getting detected. (I tried with both the units).
The paradigm is made in SuperLab 5 already.

Is it a bug in SuperLab 5.0? Is it possible to detect the old LSC400B?

The Lumina controllers should have no problem working with SuperLab 5.

Are you using them on a new computer? and more importantly, how are they connected? The LSC400B controller uses a serial port, so either your computer has a physical serial port, or it is using a USB-serial port converter.

We have one licence of 4.5 (bought earlier, installed in a old Dell laptop with Windows 10 (upgraded from Windows 7)) which is running fine, without any problem with the Lumina, and is recording the responses.

The new license is SuperLab 5.0.5 (installed in another new Dell Laptop with Windows 8). With the same USB to serial port cable and the Lumina response pads, it was not detecting the Lumina.

The new SuperLab 5.0.5 license is on a new computer. Is the USB driver installed on that computer?

One way to tell is to open the Device Manager in Windows and look at the section “Ports (COM & LPT)”. When you insert the USB-serial port adapter, a new entry should appear under that section with a name like “USB Serial”. When you unplug the adapter, the entry should disappear. Is this happening?